Full moon or half moon clips? Not for me. Maybe some day if I start shooting Bowling Pins
A Ruger Vaquero in 45 Colt wouldn't be an ugly cannon to use for plinking. Certainly tamer and softer then stout 357 Magnum loads. Those little jacked up 125 "Elephant" killers as I call them, really bark and snap the wrist. I'll take my 44 Magnum anyday as I find it more pleasant (assuming unported pistols without heavy underlugs

).
Now, to the specific topic at hand. Do you really want or need to shoot 9mm out of your wheelgun? For the hard times survivalist mentality, I can sort of see it but, the 9mm doesn't add anything unique when you consider what a 38 special will do. 38's can be exceptionally tame and cheap to shoot when you load or buy the right rounds. Personally, I like the 125JHP 38 +P's for general plinking fun. A convertible adds a little to the price but, not a lot so maybe the gadget factor of the caliber conversion is worth it.
For a dedicated plinker and target pistol, a 6 inch barrel is nice because it removes some of the sensitivity to minor aiming errors (it's all about the geometry and angles). I generally shoot underlug barrel revolvers and find the 6 inch barrel to be just about perfect for my use. More then that and they become unwieldy, shorter and the balance is off and the blast is worse (with 357's - sure the fireball in full afternoon sun is fun the first few times but, it gets old shooting a flame thrower

). A 4 inch barrel wheelgun is easier to carry around on the belt in everyday activity but, this isn't an everyday carry piece is it?
A 6 inch (plus or minus and inch) single action Ruger is a good place to start. Then figure out what caliber you really want. The Vaquero models are getting a lot of good user feedback for ergonomics but, I have never personally used one.
I would stick with the major brands. I know you don't plan on resell when you buy but, single actions are harder to resell. Having an import with little or no name recognition will really hurt the resale potential and price. Ruger's specifically, offer a lot of value for the money and use really good materials for the construction so, it's pretty hard to go wrong there.